Surveyor 3 is the third lander of the American uncrewed Surveyor program sent to explore the surface of the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

in 1967 and the second to successfully land. It was the first mission to carry a surface-soil sampling-scoop. Surveyor 3 was visited by

Apollo 12 Apollo 12 (November 14–24, 1969) was the sixth crewed flight in the United States Apollo program and the second to land on the Moon. It was launched on November 14, 1969, by NASA from the Kennedy Space Center in Florida. Commander Charles ...

astronauts

Pete Conrad Charles "Pete" Conrad Jr. (June 2, 1930 – July 8, 1999) was an American NASA astronaut, aeronautical engineer, naval officer, aviator, and test pilot who commanded the Apollo 12 mission, on which he became the third person to walk on t ...

and Alan Bean in November 1969, and remains the only probe visited by humans on another

world The world is the totality of entities, the whole of reality, or everything that Existence, exists. The nature of the world has been conceptualized differently in different fields. Some conceptions see the world as unique, while others talk ...

. The Apollo 12 astronauts excised several components of Surveyor 3, including the television camera, and returned them to Earth for study.

History

Launched on April 17, 1967, Surveyor 3 landed on April 20, 1967, at the Mare Cognitum portion of the Oceanus Procellarum (S3° 01' 41.43" W23° 27' 29.55"), in a small crater that was subsequently named

Surveyor Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. These points are usually on the ...

. It transmitted 6,315 TV images to the Earth, including the first images to show what planet Earth looked like from the Moon's surface. As Surveyor 3 was landing in the crater highly reflective rocks confused the spacecraft's lunar descent

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

. The engines failed to cut off at in altitude as called for in the mission plans, and this delay caused the lander to bounce on the lunar surface twice. Its first bounce reached the altitude of about . The second bounce reached a height of about . On the third impact with the surface – from the initial altitude of , and velocity of zero, which was below the planned altitude of , and very slowly descending – Surveyor 3 settled down to a soft landing as intended. This Surveyor mission was the first that carried a surface-soil sampling-scoop, which can be seen on its extendable arm in the pictures. This mechanism was mounted on an electric-motor-driven arm and was used to dig four trenches in the lunar soil. These trenches were up to deep. Samples of soil from the trenches were placed in front of the Surveyor's television cameras to be photographed and the pictures radioed back to the Earth. When the first lunar nightfall came on May 3, 1967, Surveyor 3 was shut down because its solar panels were no longer producing electricity. At the next lunar dawn (after 14 terrestrial days, or about 336 hours), Surveyor 3 could not be reactivated, because of the extremely cold temperatures that it had experienced. This is in contrast with the Surveyor 1, which was able to be reactivated twice after lunar nights, but then never again. Surveyor 3 became famous after the crew of

used it as a landing target site. Landing within walking distance on November 19, 1969, the astronauts took several pictures of the probe and removed a scoop from the probe's soil mechanics-surface sampler, a section of unpainted aluminum tube from a strut supporting the Surveyor's radar altimeter and Doppler velocity sensor, another section of aluminum tube that was coated with inorganic white paint and a segment of television cable wrapped in aluminized plastic film and the Surveyor 3's television camera which were returned to Earth. Surveyor 3 is the only probe visited by humans on another world.

Science instruments

Television

The television camera on Surveyor 3 consisted of a

vidicon Video camera tubes are devices based on the cathode-ray tube that were used in television cameras to capture television images, prior to the introduction of charge-coupled device (CCD) image sensors in the 1980s. Several different types of tubes ...

tube, two 25 and 100 millimeter

focal length The focal length of an Optics, optical system is a measure of how strongly the system converges or diverges light; it is the Multiplicative inverse, inverse of the system's optical power. A positive focal length indicates that a system Converge ...

lenses, shutters, clear, red, green and blue

optical filters Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultravio ...

, and an iris mounted along an axis inclined about 16 degrees to the central axis of the spacecraft. The TV camera was mounted under a mirror that could be moved in

azimuth An azimuth (; from ) is the horizontal angle from a cardinal direction, most commonly north, in a local or observer-centric spherical coordinate system. Mathematically, the relative position vector from an observer ( origin) to a point ...

(horizontally) and elevation (vertically). The operation of the camera was completely dependent upon the receipt of proper commands from the Earth. Frame-by-frame coverage of the lunar surface was obtained over the complete 360 degrees in azimuth, and from +40 degrees above the plane normal to the camera's Z-axis to −65 degrees below this plane. Both 600-line and 200-line modes of TV camera operation were used. The 200-line mode transmitted over an

omnidirectional antenna In radio communication, an omnidirectional antenna is a class of antenna (electronics), antenna which radiates equal radio power in all directions perpendicular to an Cartesian coordinate system, axis (azimuthal directions), with power varying wi ...

and scanned one frame every 61.8 seconds. A complete video transmission of each 200-line picture required 20 seconds and used a bandwidth of 1.2 kHz. The 600-line pictures were transmitted over a

directional antenna A directional antenna or beam antenna is an antenna that radiates or receives greater radio wave power in specific directions. Directional antennas can radiate radio waves in beams, when greater concentration of radiation in a certain directio ...

. These pictures were scanned as often as once every 3.6 seconds. Each 600-line picture required a nominal one second to be read from the image vidicon, and its transmission required a 220 kHz bandwidth, using digital picture transmission. The TV photos were displayed back on the Earth on a slow-scan TV monitor that was coated with a long-persistence

phosphor A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or ...

. Its persistence had been selected to match the nominal maximum

frame rate Frame rate, most commonly expressed in frame/s, or FPS, is typically the frequency (rate) at which consecutive images (Film frame, frames) are captured or displayed. This definition applies to film and video cameras, computer animation, and moti ...

. One frame of TV identification was received for each incoming TV photo, and the picture was displayed in real-time at a rate compatible with that of the incoming image. These data were recorded on a video magnetic-tape recorder. The camera returned 6315 pictures between April 20 and May 3, 1967, including views of the spacecraft itself, panoramic lunar surveys, views of the mechanical surface digger at work, and of an April 24 eclipse of the Sun by the Earth. The Apollo 12 Lunar Module landed near Surveyor 3 on November 19, 1969. Astronauts Conrad and Bean examined the spacecraft, and they brought back about of parts of the Surveyor to the Earth, including its TV camera, which is now on permanent display in the

National Air and Space Museum The National Air and Space Museum (NASM) of the Smithsonian Institution is a museum in Washington, D.C., in the United States, dedicated to history of aviation, human flight and space exploration. Established in 1946 as the National Air Museum, ...

Washington, D.C. Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with ...

Analysis of the camera found that it withstood 947 days in the vacuum of space, including 32 two-week lunar nights with temperatures dropping below , in good condition. Most major components were functional and undamaged. Some changes were caused by temperature extremes, micrometeorite strikes, and manufacturing errors. The recovered sampler scoop was also in good condition with little change other than some sun-induced fading of the paint. File:Surveyor 3 Fig 7-41b1.jpg, Panorama of the mare surface File:Surveyor 3 Fig 3-44.jpg, Angular blocks, up to in diameter, which form part of a strewn field of blocks that surround a sharp-rim crater in diameter File:Surveyor 3 Fig 7-41b2.jpg, Similar view but with different lighting File:Surveyor 3 Fig 3-53.jpg, Blocky fragments on north wall of crater in which the spacecraft is located

Soil mechanics surface sampler

The soil mechanics surface sampler was designed to dig, scrape, and trench the lunar surface and to transport lunar surface material while being photographed so that the properties of the lunar surface could be determined. The sampler was mounted below the television camera and consisted primarily of a scoop approximately long and wide. The scoop consisted of a container, a sharpened blade, and an

electric motor An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a electromagnetic coil, wire winding to gene ...

to open and close the container. A small footpad was attached to the scoop door to present a flat surface to the lunar surface. The scoop was capable of holding a maximum quantity of approximately diameter of solid lunar material and a maximum of of granular material. The scoop was mounted on a

pantograph A pantograph (, from their original use for copying writing) is a Linkage (mechanical), mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a se ...

arm that could be extended about or retracted close to the spacecraft motor drive. The arm could also be moved from an azimuth of +40 to -72 degrees or be elevated by motor drives. It could also be dropped onto the lunar surface under force provided by gravity and a spring. The surface sampler performed seven bearing tests, four trench tests, and thirteen impact tests. The total operating time was 18 hours, 22 minutes on ten separate occasions. Measurements of motor currents and forces applied to the surface were not obtained due to the state of the spacecraft

telemetry Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', 'far off', an ...

following landing on the lunar surface. However, estimations were possible. The small

spring constant In physics, Hooke's law is an empirical law which states that the force () needed to extend or compress a spring (device), spring by some distance () Proportionality (mathematics)#Direct_proportionality, scales linearly with respect to that ...

of the torque spring precluded the determination of density from the impact tests. Penetrations of were obtained from the bearing tests, and a depth was reached during trenching operations. The design of the mechanism and its electronic auxiliary was more than adequate for the lunar surface operations. The scoop was also returned to Earth by the Apollo 12 astronauts and is currently on display at JPL. File:NASM-SI-2007-29754.jpg, An engineering model of Surveyor 3, S-10, used for thermal control tests, reconfigured to represent a flight model of Surveyor 3 or later, at the

(NASM) File:NASM-A19700294000-NASM2018-02492.jpg, Three-quarter view from below of Surveyor engineering model (NASM) File:Surveyor3camera.jpg, Surveyor 3 camera brought back from the Moon by Apollo 12, on display at NASM File:Surveyor3scooping.jpg, Surveyor 3 scoops, photographed by the Apollo 12 astronauts File:Surveyor 3 Soil Mechanics Surface Sampler.jpg, Soil mechanics surface sampler from the Surveyor 3 spacecraft returned to Earth by the crew of Apollo 12

Apollo 12 and the possibility of interplanetary contamination

The Surveyor 3 landing site was later selected also as the landing target for the

Lunar Module The Apollo Lunar Module (LM ), originally designated the Lunar Excursion Module (LEM), was the lunar lander spacecraft that was flown between lunar orbit and the Moon's surface during the United States' Apollo program. It was the first crewed s ...

of the Apollo 12 crewed lunar mission in 1969. Several components of the Surveyor 3 lander were collected and returned to the Earth for study of the long-term exposure effects of the harsh lunar environment on human-made objects and materials. Although space probes have returned to Earth in the decades since Apollo 12, this remains the only occasion on which humans have visited a probe that had been sent off-world. It is widely claimed that a common type of

bacterium Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the ...

, '' Streptococcus mitis'', accidentally contaminated the Surveyor's camera prior to launch, and that the bacteria survived dormant in the harsh lunar environment for two and a half years, supposedly then to be detected when Apollo 12 brought the Surveyor's camera back to the Earth. This claim has been cited by some as providing credence to the idea of interplanetary

panspermia Panspermia () is the hypothesis that life exists throughout the universe, distributed by space dust, meteoroids, asteroids, comets, and planetoids, as well as by spacecraft carrying unintended contamination by microorganisms,Forward planetary c ...

, but more importantly, it led NASA to adopt strict abiotic procedures for space probes to prevent contamination of the planet

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

and other astronomical bodies that are suspected of having conditions possibly suitable for life. Most dramatically, the ''Galileo'' space probe was deliberately destroyed at the end of its mission by crashing it into

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined a ...

, to avoid the possibility of contaminating the Jovian moon Europa with bacteria from Earth. The ''Cassini'' probe also impacted

Saturn Saturn is the sixth planet from the Sun and the second largest in the Solar System, after Jupiter. It is a gas giant, with an average radius of about 9 times that of Earth. It has an eighth the average density of Earth, but is over 95 tim ...

at the end of its mission in 2017. However, independent investigators have challenged the claim of surviving bacteria on Surveyor 3 on the Moon. There is a possibility the contamination was caused by using a non-airtight container, or when the samples were being taken in the clean room after Apollo 12.

Lunar Reconnaissance Orbiter

In 2009, the

Lunar Reconnaissance Orbiter The Lunar Reconnaissance Orbiter (LRO) is a NASA robotic spacecraft currently orbiting the Moon in an eccentric Polar orbit, polar mapping orbit. Data collected by LRO have been described as essential for planning NASA's future human and robotic ...

(LRO) photographed the Surveyor 3 landing site in some detail, in which surrounding astronaut foot tracks could also be seen. In 2011, the LRO returned to the landing site at a lower altitude to take higher resolution photographs.

References

External links

Surveyor Program Results (PDF) 1969

Analysis of Surveyor 3 material and photographs returned by Apollo 12 (PDF, 24 MB) 1972

Surveyor 3 images
at Lunar and Planetary Institute
Surveyor Site III Lunar Map
at Lunar and Planetary Institute
Surveyor Site III Lunar Photomap
at Lunar and Planetary Institute {{Use American English, date=January 2014 3 Spacecraft launched in 1967 Missions to the Moon Apollo 12 Spacecraft launched by Atlas-Centaur rockets Soft landings on the Moon Alan Bean Pete Conrad 1967 on the Moon Space archaeology